Processor modules have become popular in recent years as a means for providing reliable and efficient computer system upgrades. In a processor module, a processor is mounted to a circuit panel containing electrical interconnection paths, for example a printed circuit board, along with support electronics, for example random access memory (RAM) in the form of processor cache. Module electronics communicate with electronics mounted to a computer motherboard via an interface in the form of a high-speed connector. Ideally, as system clock rates increase, and processor functions evolve, the outdated processor module assembly can be removed from the motherboard at its connector and replaced by an upgraded module capable of operating at the higher rate, and/or with improved functionality.
While some contemporary systems allow for an upgrade or replacement by a processor module within a same processor family, or having the same processor architecture, as the original, such systems do not accommodate replacement by a processor module from a different processor family, or different architecture.
The present invention is directed to a motherboard interface for a processor module that accommodates processors of different processor architectures sharing a common high-speed system bus architecture. In this manner, an interface is provided such that a processor module including a processor of a first architecture, for example the x86(trademark) family of processors produced by AMD Corp., can be replaced by a processor module including a processor of a second, and distinct, architecture, for example the Alpha(trademark) family of processors produced by Compaq Computer Corp. The present invention thus allows a multiple of completely different processor architectures to share a common motherboard, thereby providing a system that can be field-upgraded by processor modules of different architectures, or to simply allow the same motherboard to be employed in two different products of different processor architectures.
The present invention comprises a system for a motherboard adapted for interfacing with processor modules of a plurality of different processor architectures. The system comprises an interface for communicating with a processor module inserted at the motherboard. The interface receives an identifier signal from the processor module. The identifier signal identifies the processor module architecture. An architecture selection circuit selectively exchanges processor architecture specific signals with the processor module based on the identifier signal.
In a preferred embodiment, the interface comprises a connector for exchanging signals between the motherboard and processor module. The interface further communicates processor architecture specific signals and processor architecture common signals.
The architecture selection circuit may comprise a multiplexer bank for outputting one of a plurality of processor architecture specific signals to the interface selected by the identifier signal. The architecture selection circuit may further comprise a demultiplexer bank for inputting one of a plurality of processor architecture specific signals from the interface selected by the identifier signal.
The system may further comprise an initialization memory bank comprising processor architecture specific data stored in memory, the data being selected based on the identifier signal. The memory preferably comprises processor architecture specific BIOS ROM. The processor architecture specific data is preferably transferred to the processor module via processor common signals on the interface.